SheetDiff™ is a schema-agnostic Google Sheets™ add-on that compares spreadsheet data and generates detailed quality assurance reports — all inside Google Sheets™.

Whether you're comparing transcript versions, reviewing translations, reconciling financial data, or auditing any tabular data — SheetDiff™ finds every difference, color-codes it, and gives you a professional report in seconds.

=== THREE POWERFUL COMPARISON MODES ===

🔍 STRUCTURAL DIFF Compare an original snapshot against an edited version. Every row is categorized:
• UNCHANGED — identical rows
• MODIFIED — text or data changes (with inline green/red highlighting)  
• SPLIT — one row became multiple rows
• MERGED — multiple rows combined into one
• ADDED — new rows in the edited version
• DELETED — rows removed from the original

📊 CELL-BY-CELL COMPARISON Compare a baseline sheet against one or more sheets, cell by cell:
• Three compare modes: Exact, Normalized (smart), and Fuzzy (similarity-based)
• Three row alignment modes: Positional, Key-based (match by key columns), or Content-based auto-alignment (smart row matching by text similarity)
• Per-sheet match statistics and aggregate scores
• Compare across multiple sheets simultaneously

🔎 DUPLICATE FINDER Find duplicate rows within a single sheet or across multiple sheets:
• Self-compare mode: scan one sheet for internal duplicates
• Cross-sheet mode: find duplicates across 2 or more sheets
• Select which columns to match on (composite key support)
• Color-coded results: orange = duplicate, green = unique
• Shows which sheets and rows contain each match
• Merge Duplicates: One-click bulk removal of duplicate rows directly from the source sheets

=== KEY FEATURES ===

✅ SCHEMA-AGNOSTIC — Works with any column layout. No fixed template required.

✅ AUTO-DETECT COLUMNS — Click one button and the add-on detects speaker, timestamp, transcript, and event columns from your headers. Supports camelCase, snake_case, and plain-English naming.

✅ COLOR-CODED DIFF VIEWER — A dedicated output sheet with color-coded rows, inline text diffs (bold green = added, red strikethrough = removed), and collapsible sections.

✅ QA METRICS — Word Error Rate (WER), Character Error Rate (CER), and Segment Error Rate (SER) computed automatically.

✅ EXPORTABLE QA REPORT — Generate a clean, shareable report sheet with all metrics, change logs, and metadata — perfect for team reviews and audits.

✅ SNAPSHOT WORKFLOW — Commit a snapshot of your original data before editing. Run the diff at any time to see exactly what changed.

✅ CUSTOM TRANSFORM RULES — Define your own find/replace rules (plain text or regex) applied before comparison. Strip URL prefixes, normalize phone formats, remove tracking codes — all without modifying your source data. Rules are mode-specific, letting you tailor transforms for Structural vs. Cell-by-Cell comparison independently.

✅ CROSS-SPREADSHEET IMPORT — Visually browse your Google Drive™ directly from the Compare Picker to import sheets from other files. Compare data across separate spreadsheets without manual copy-pasting or URL fiddling.

✅ COMPARE PICKER — A visual sheet selector with batch complexity estimates. Pick your baseline and compare sheets, see row counts, and get an estimated run time before launching the comparison.

✅ MULTI-LANGUAGE SUPPORT — Full Unicode normalization across 6 numeral systems (Arabic, Persian, Devanagari, Bengali, Thai, fullwidth). Optional diacritics stripping for accent-insensitive comparison (French é→e, German ü→u, Russian Ё→Е).

✅ PERFORMANCE OPTIMIZED — Batch rendering (5–10× faster than cell-by-cell API calls), configurable output row limits, auto-hide unchanged rows for large datasets.

✅ CONFIGURABLE — Similarity thresholds, column mapping, row alignment modes, inline diff toggle, max output rows, hide unchanged/matching rows, custom transforms — all adjustable in the settings sidebar.

=== WHO IS THIS FOR? ===

• Localization teams — compare original vs. post-edited transcripts
• Translation reviewers — diff source vs. target language versions
• Financial analysts — reconcile versions of reports and budgets
• Data teams — audit spreadsheet changes, find duplicates, and clean data
• Project managers — track what changed between deliverable versions
• Anyone who needs to compare two (or more) sheets in Google Sheets™

=== GETTING STARTED ===

Install the add-on
Open any spreadsheet → Extensions → SheetDiff™
Click ⚙️ Settings → choose your comparison mode → Auto-Detect or manually map columns
For Structural Diff: click 📸 Commit Snapshot to save your original data
Click 🔍 Run Comparison → use the Compare Picker to select your sheets
Review the color-coded Diff Viewer → click 📄 Export Report for a shareable summary

=== SUPPORT & LINKS ===

🌐 Developer: mohamedyaakoubi.live
📧 Contact: amirrak8@gmail.com

Developed by Mohamed Yaakoubi.

Google Sheets™ and Google Drive™ are trademarks of Google LLC.